Submitted my first Shopify App

I am a full-stack web developer working on projects with different stacks.
Since last summer, I started working on some Shopify projects building themes from scratch for our clients.

However, Lately, I wanted to start my first side project, I know that many fields are saturated (mobile apps...) so I thought about other platforms' apps such as Wix, Shopify, Weebly... and since I have some experience with Shopify, I decided to start with it.

My app is so simple, it allows you to import your customers' emails to your mailchimp account with a single button. I made it simple in order to get familiar with Shopify apps and their submissions terms and how long it takes for review... if everything went well with this one, I will think seriously to build bigger apps (I prepared a list of some ideas)

While waiting for the submission review, I would like to know if there are some of you guys who have experience with shopify apps, what are your tips, what do you promote your apps...

Looking forward to reading your comments.