VERY FRUSTRATING. I honestly love the app. I use it everyday for hours and hours. There have always been a few glitches, but nothing that I found too annoying, but when the app started lagging, then freezing, then losing the content I had just spent time writing, grrrr. lately, it just stops recognizing that I am writing, then hangs. Also issues with crashing when exporting a notebook to pdf. suggesting that it doesn't want to export larger notebook. idk my favorite app is becoming unusable.