Spellcheck is available in TexMaker in the Edit menu. However, running it throws up this error: "Error: Can't open the dictionary".
A bit of searching revealed that myspell is not available, but hunspell is. You'll find the en_US.aff and en_US.dic files in /usr/share/hunspell.
Now, in TexMaker's menu, go to Options > Configure TexMaker > Editor > Spelling Dictionary, and enter /usr/share/hunspell/en_US.dic.
Viola! Now when you run spellcheck, it'll work.
