Hi there! I understand you're having trouble with the Tody app closing unexpectedly on your iPhone. Let's work through this together.

First, can you let me know if this issue started after a specific update, or has it been happening for a while? Also, which version of the Tody app are you currently using? This information can help me better understand the situation.

In the meantime, here are a few initial steps that often help resolve app issues:

1. Force Close the App: Swipe up from the bottom of your screen (or double-click the Home button if your iPhone has one) to see the app switcher. Find the Tody app and swipe it up to close it completely. Then, reopen it to see if it works.

2. Restart Your iPhone: Sometimes, a simple restart can clear out temporary glitches. Just turn off your iPhone and turn it back on.

3. Check for Updates: Ensure both your iPhone's iOS and the Tody app are up to date. To check for iOS updates, go to Settings > General > Software Update. For the Tody app, open the App Store, tap on your profile picture, and scroll down to see if an update is available.

Let me know how these steps work out, and if the issue persists, we can look into some advanced troubleshooting!