I just installed macOS Mojave this afternoon without difficulty, but found that two of my apps needed updating as a result. They are Printopia (to v3.0.12) and anyTrans (to v7.0.1). All of the other apps that I have had already been updated to newer versions prior to my upgrading to Mojave.
I would say that my biggest issue in migrating from macOS High Sierra to macOS Mojave has been the password manager, 1Password. In macOS Mojave, Apple has made certain changes to its operating system that resulted in the "browser extensions" used by many password managers to become inoperable. I didn’t know this at the time I chose to upgrade to Mojave but have since learned that these changes have resulted in such dynamic changes to 1Password that its developer created a new type of browser extension that he has dubbed the “1Password X project”. Basically, what I had to do was to upgrade my version of 1Password to v7.2 (the one designed for Mojave), throw out my existing “works with High Sierra” (Google) Chrome browser extension, and replace it with a new "1Password X" browser extension. The 1Password v7.2 upgrade was made somewhat difficult because even though I had purchased my copy of 1Password through the App Store, the v7.2 version of 1Password has yet to be posted there (as of this writing) and must be downloaded instead from the vendor’s (agilebits) web site, URL:
https://app-updates.agilebits.com/product_history/OPM7. The new v7.2 browser's "1Password X" browser extension is already available in the Chrome Web Store.
With the new software in hand, you upgrade your existing copy of 1Password (I had v7.1.2 previously) and swap out your existing browser extension for the "1Password X" one. Once this is done, you’ll find that 1Password now works differently in the Chrome browser. When needing to fill in a password at any given website, instead of clicking on the browser extension icon (in the extension tray) to fill in the password as before, the 1Password icon actually appears on the web page where the password needs to go. You click on that icon, your login password choices appear, and you select one which, in turn, supplies the password to the web page’s password field. One of the casualties of this approach you will likely notice is that you will now need to press the Return key to submit your Password choice to the web page. In the past, the old 1Password browser extension offered an “auto submit” feature which supplied the password and automatically submitted it to the web page and the new "1Password X" extension, which is a stand-alone program unto itself, does not. It is my understanding that because of the underlying programming changes made to macOS within Mojave, the addition of an “auto submit” feature is no modest undertaking for the developer and therefore does not exist presently.
This is not just a Chrome issue with 1Password. It exists also with the Safari and Firefox web browsers as well. When you first launch Safari, after upgrading to Mojave, and go to use 1Password, Safari then tells you upfront that you need a new browser extension that is only available from its Safari Extensions collection. This is a very straight-forward process and easily accomplished.
With Firefox, the process of upgrading is much the same as that for Google Chrome with the only real difference being the you’ll find the new "1Password X" browser extension in the Firefox Manage Add-Ons section of the browser rather than the Chrome Web Store.
All this change takes some getting used to, but other than the loss of the “auto submit” feature, I found that this new version of 1Password pretty much worked the same as the previous one.
Also, I just discovered that if you are using a Logitech keyboard, you should update your Logitech Options application. While working with Excel and Evernote, I discovered that the keyboard shortcuts for Copy and Paste had been remapped from Cmd+C and Cmd+V to Ctrl-C and Ctrl+V (as a result of my upgrading to macOS Mojave). I checked my copy of the Logitech Options app and found that an updated version was available. So I updated and now the keyboard mapping is correct again. Thank you Logitech!