Yes I have kept a digital daily diary for years. I highly recommend it. It can be as simple as a couple of lines about where I went or what I did did, through to extensive personal essays breaking down what I thought about something or my impressions. I keep it open format and mix prose-like writing with bullet points, or pasting in images or screenshots.

It is excellent to go back and be able to see moments or feelings and the evolution of ideas and thoughts. Without it I would somehow feel the days are just blending into each other!