I encourage all Android developers / business owners to read this one, as you will surely be surprised at how easily and without any justification your fine app can come out to an end, as big companies and law firms (Google, Instagram, AppDetex) can act however they like and ruin small businesses around.
I've been developing apps on Google Play for about 10 years now.
My recent app "InPlan - Planner for Instagram" got suspended from Google Play lately, for no legal reasons and I don't receive any answers either from Google or the complainant.
InPlan was a utility app for Instagram, its goal is to help users or business accounts to preview their feed, plan and schedule their future posts before they publish on Instagram. It is a pretty big niche and there are some heavy competitors out there. You may view here competitor apps: https://play.google.com/store/search?q=preview+instagram+feed&c=apps
The app was about 6 months old and I've been working on for about 2 years, the app has started getting a nice traction of about 300 daily downloads in its recent weeks.
Web archive url:
15th August: First notification I received from Google in regards to trademark infringement policy violation:

So the claim is the following:
The app infringes Instagram’s rights by using the Instagram Spectrum Multi-Color Gradient in the app branding in a manner that is likely to create confusion by implying an association or other relationship with, or authorization by, Instagram when no such relationship or authorization exists. The app also infringes Instagram’s rights in the registered INSTAGRAM mark by using “for Instagram” in the app branding without any other branding that is distinctive to the app. Such use is likely to create confusion by implying an association or other relationship with, or authorization by, Instagram when no such relationship or authorization exists.
The complainant contact person is someone in the name of AppDetex company.
So meet AppDetex: Instagram has hired a third party company called AppDetex. Their goal is as they state in their website: "finds and removes threats to your brand online. We watch your back while you focus on building customer trust, increasing sales, .." You may read more in their website: https://www.appdetex.com/
Also, it worth noting that my app has been approved by Instagram's own App Review process and I was complying with all of their guidelines. The app was approved to use Instagram APIs to access users data, etc..
At the time of my app receiving the complaint, the app icon was the following:

So reading on the Instagram Spectrum Multi-Color Gradient trademark in https://tsdr.uspto.gov/#caseNumber=5299116&caseSearchType=US_APPLICATION&caseType=DEFAULT&searchType=statusSearch
it describes the following:
The mark consists of a rounded square wherein the bottom left corner is yellow, fading to orange and the bottom right corner is red and pink. The top of the square is blue and purple, fading to pink. There is another rounded square superimposed upon the larger square in white containing a white circle and another smaller white circle above and to the right of the larger circle.
Well, as you may read, the mark clearly describes Instagram's app icon, (Two squares inside each other and their gradient colors).
My app icon clearly shows a different shape than Instagram's, but I still decided to change the colors of the app icon so that I can resolve that issue with them at least.
August 17th (two days after receiving the notice): The new app icon was already updated on Google Play.

After that, I immediately reached out to the complainant via the email mentioned in the notice from Google, telling them I have changed the app icon.
BUT in regards to their second claim saying that I'm violating trademark policy by using the "for Instagram" phrase in the app branding is for sure an incorrect claim.
As Instagram allow using the "for Instagram" in their own brand guidelines page:
https://www.facebook.com/brand/resources/instagram/instagram-brand/
Quote from the brand guidelines terms:
If you offer an app, website or a product or service that uses the Instagram APIs or is otherwise compatible with or related to Instagram, you may only use Instagram to say that your app is "for Instagram" or that the name of your campaign is "on Instagram" in a descriptive manner.
As I mentioned before, the app branding title is "InPlan - Planner for Instagram", so it is definitely using "for Instagram" in descriptive manner, as allowed.
Also, without allowing this explicitly in their brand guidelines page, it probably should be categorized under the "fair use" of trademarks.
Moreover, there are many competitor apps using the "for Instagram" as a part of their branding freely, but this is not a part of my claim as I never violated the trademark policy anyways.

August 25th (8 days after my emailing them): I received an email back from the complainant, basically just an email template telling me to read the policies and guidelines of Instagram, they didn't refer to the specific case of mine.

Understanding that I don't have any partner to resolve the notice from Google, I just kept my app branding as is, thinking that Google team will look into the case and see that the app doesn't infringe any trademark policy and close the notice.
October 7th: (Almost 2 months after the first notice): I received the exact same notification I originally received in August 15th regarding violation Instagram's trademarks.
October 20th (13 days after last notice): My app got suspended from Google Play, and here's the original notice:

I immediately reached out to Google via the appeal form and saying that my app doesn't violate any trademark policy of Instagram, here's my original claim to them via the appeal form:
"The app infringes Instagram’s rights by using the Instagram Spectrum Multi-Color Gradient in the app branding" - False statement - the app branding doesn't make use of the Instagram Spectrum Multi-Color Gradient, as it uses only red-orange colors. U.S registration NO: 5299116.
"The app also infringes Instagram’s rights in the registered INSTAGRAM mark by using “for Instagram” in the app branding without any other branding that is distinctive to the app" - False statement. "InPlan - Planner for Instagram" has distinctive branding by having the app name "InPlan", as the first word of the app title, then using the hyphen symbol in order to describe the app, thus, using "for Instagram" in descriptive manner.
Using "for Instagram" in descriptive manner is permitted in Instagram's brand guidelines: https://en.instagram-brand.com If you offer an app.. you may only use Instagram to say that your app is "for Instagram" ... in a descriptive manner. and they redirect me to solve the issue with the complainant, but the complainant won't even answer and ignore my requests to talk to them.
October 23rd: Google Play team has responded to my appeal saying that they will not be reinstating the app and that I should address the complainant directly and resolve it with them, the complainant should allow Google Play team to reinstantiate the app.

Moving on, understanding that Google will not come in and do the judging regarding this case, I tried to contact the complainant once again via email, saying that I'm eager to resolve the issue, trying to understand which policy I actually violated.

I never received any response from the complainant.
I've also been trying to reach out to AppDetex company for one week now and speak with one of their team members to get a relevant response regarding the complaint. But their reception keeps hanging up on my calls. (I do have some call recordings with evidence on them ignoring my request and hanging up).
While trying to reach out to the complainant, I submitted another appeal to Google, telling them the complainant won't respond me. But Google Play team keeps telling me (with the same templated email of course) to contact the complainant directly by my own.
I also consulted with a professional trademark lawyer. He said that the justice is with me on this case, but I'm in a dead-end because Google telling me to speak with the complainant, and the complainant interest is that my app will keep being suspended, so the complainant will obviously not permit me to reinstantiate my app.
Why is it that Google just suspending my app with false legal reasons? They received a complaint from a third party and won't judge the statements of the complainant by their own.
I really think that this can happen to all of the developers of Google Play. My goal in publishing this post is to raise awareness and change the way Google treat developers to their platforms as this is truly a shame.
In the meanwhile, spreading this story around in social media can be good enough and might help all of us, as we should have a far more superior status by Google.
Also, If you have any idea of what steps I should take in order to reinstate the app it would be highly appreciated.
I've also published this story on reddit, please help to get some traction in the reddit post!
https://www.reddit.com/r/androiddev/comments/yu2ch7/app_got_suspended_from_google_play_without/
Thanks all for reading this!
Such annoying reckless behavior from big tech!! Please keep us posted when you make some progress in your investigation