Spellcheck, Thesaurus, Themes, Syncing & Security
As others have stated, I think spellcheck is an absolute must. Currently, the lack of this feature is the only reason I'm putting off subscribing to the service.
Beyond that, a thesaurus would be a very welcome plus.
Additionally, while I like the Shaxpir interface as-is (very clean and elegant), I would prefer a few different themes to choose from, even if they're limited to dark and light themes. I do my best writing late at night, and staring at a clean white screen is difficult. Other utilities offer customizable themes or day/night themes, allowing you to choose a GUI that is easier on the eyes late at night.
Maybe it's just me (entirely possible), but the sync feature doesn't seem to work at all. I've been using a trial of the product on two different PCs for several weeks now, and even though I log into both apps with the same account, nothing I create on either PC ever shows up on the other. I mean nothing. At this point I don't know if it's a bug, a firewall issue (custom ports that need to be opened?), or the fact that my account is a trial account and not a paid account. The ability to natively sync without the aid of Dropbox/OneDrive/etc... is a major selling point, but not if it doesn't work.
Finally, it would be good to know how secure the (A) sync mechanism and (B) the hosted servers are. At the moment I store all my data inside a single encrypted file which I sync between PCs via DropBox. I do this because should DropBox ever be compromised I don't want my data to be at risk, so encrypting everything before it enters their cloud adds one more layer of security. With Shaxpir I don't have this option, so I need to know the native transmission and storage of my files is completely secure. I'm not saying it's not, but there's no information on this website (that I've found) which discusses this aspect of the service in detail.
Anyway, I love the idea of the product and I hope to subscribe at some point, but it just doesn't feel ready quite yet.
Themes for me are a very low priority item - I would almost say give only two choices - light and dark. Get the app to function properly with the most valuable features.
I would like a special dictionary for EACH story. Character and place names will not read correct in standard spellcheck. allowing me to add an additional dictionary for each story makes spelling easier.