Mobile data is a valuable commodity and Google's Datally — formerly Triangle — aims to help you conserve it. In certain countries, data can be extremely expensive, so the app can really come to the rescue during billing periods in which you use your phone a lot.
Datally recently introduced new features such as a Guest mode and daily data limits. The latest update, to version 1.6, adds two new tools. Bedtime mode helps you save even more data while you sleep, and Emergency bank lets you set aside some of your allowance just in case you run out.
Once you've set up a reserve in Emergency bank, you can then set an expiry date that matches up with your next billing period. Bedtime mode is controlled by a simple start and end time, and it can also be paused. Use this with Android's new Digital Wellbeing/DND settings and your phone will essentially shut down at a time of your choosing, forcing you to sleep and saving data at the same time.
If you haven't got the v1.6 update through the Play Store yet, you can grab it from APK Mirror.