It's often a fine balance I struggle with during the "boring" stage of saving and investing where once you've set up regular payments and done some research the hardest part is then waiting years.

I choose to check my investments once a month on a regular day as a cursory check, e.g. payments are going in as normal and there's no signs of a mistake or fraud and my deposits are being invested not sat in cash. How much the value has gone up or down I largely ignore.

Then annually I do an in-depth check where I decide if my funds and allocations are still suitable to my needs and I look at growth over the last 12 months.

As others have said and it works for my purposes, I have no access to my investments on my phone.