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