How to sync data between different devices

Question

I am planing to implement an app and I have come to a point where I don't know what is the best approach.

Scenario:

I have an app where I am making a todo list and I am adding 3 items. I use my phone for this. Then I take my tablet and want to continue adding another task. Then after a while I take my wife's phone and want to add 2 new tasks.

Basically I want to have a very simple way of storing the tasks online and be able to sync it with the app.

I am seeing two possible ways:

• have a web server with a database + web service calls. This has the disadvantage of having a host paid, learn some extra mysql + web service techniques.

• store somehow the data on cloud and allow the app by login to access an account which stores the file. I am thinking here at something like Google Drive / Dropbox. But I don't know how I would be able to sync only the updated values, not the whole file. Because I am thinking, if I store all the tasks into one file, each time I update the file, I'll need to upload it fully, which is not the best approach.

I am open to any advices. What approach would you recommend ?

Answer 1

There's also Google Drive's "Application Data" folder.

https://developers.google.com/drive/android/appfolder

This has the advantage of using the user's storage space.