PicCollage (Android. Over 70 million downloads)
“With over 70 million downloads, PicCollage is your new favorite app ❤. It’s a party with your photos!
PicCollage allows you to create amazing collages using your photos, stickers, text and frames. Once you’re done, share it to Pic Collage, Facebook, Twitter, Instagram and also also email it! Perfect for keeping memories”
I developed the first version of PicCollage for Android. Since then the app has become insanely popular and they now have entire offices of coders actively maintaining the app, which is getting better all the time. I am no longer involved in the development of this app but I am of course very pleased to see it doing so well – that many downloads is staggeringly good in anyone’s book!