Ever since I launched www.pesatime.com 3 weeks ago, I have received a couple of requests to expose an API that allows developers to record expenses/income through an API.
It's been a 3 day job to work on the API backend, Create Integration docs and deploy all of them and this has been a success. Here is the API docs website I created with @gitbook
For those of you wondering what Pesatime is, it's basically a super simple book keeping application for small businesses.
You can give it a try it here (www.pesatime.com) - Its free, no credit card is required