Uosk
Unicode On-Screen Keyboard: insert text snippets into any Windows app
...Clicking one button the text snippet is pasted into any text editor (Notepad, WordPad, MS Office, OpenOffice...). You can edit snippets directly in Uosk, and save them as a new txt file. The snippet can also be copied to clipboard.
It's basically a virtual keyboard with ability to set any amount of characters in one button.
Uosk comes with some preset keyboard: Arabic, box drawing, Devanagari, emoji, Greek, Hebrew, Hiragana, IPA, Katakana, Russian and Windows-1252.