Is there any closed source android app that you wish had a good open source alternative?

https://programming.dev/post/15144507

Is there any closed source android app that you wish had a good open source alternative? - programming.dev

I’m currently looking to develop an open source app that can help somebody. I’m currently out of ideas, so I’d like to heard if from you guys. Sorry if it seems to lazy to ask for ideas like that, I just thought that I could do it since the result will be a free app.

A lightweight office suit
Collabora Office for Android & iOS - Collabora Office and Collabora Online

Collabora Office for Android & iOS The Mobile Apps of Collabora Office Latest Release Announcement & Latest Release Notes Collabora Office for Android and iOS is the mobile office suite of Collabora Office, which is based on LibreOffice, the world’s most widely used open source office suite. Today’s world of work is far more distributed and mobile, […]

Collabora Office and Collabora Online
Can this be considered lightweight? not complaining, just curious
I’d argue no office suite is lightweight by design. If lightweight is important you should use markdown or LaTeX