1) Canva
Great app for designing social media posts.
2) Google Keep
With Google Keep you can keep your notes on cloud organize them and access on every device with your Google Account.
3) Glitch Lab
Simple but creative app for adding glitch and many effects to your photos.
4) Pexels
Free stock photos if you need.
5) Autodesk Sketch
I've using this drawing app for a year and I recommend you.