There appears to have been two programs for the Sinclair QL called QSPELL, one by Eidersoft and a second by Quantum Mechanics. It is of course possible that Eidersoft merely published the program developed by Quantum Mechanics.
QSPELL is a spelling checker for Quill, with a 25,000 word dictionary which can auto-learn words and be used to solve crosswords, anagrams and puzzles.
Alas, the downside of QSpell was that it is not interactive - it can only check a finished Quill document, rather than checking as you type.
You could however, integrate QSpell with Psion's Quill in that by pressing CTRL F3, within Quill, you brought up a QSpell menu bar, which allowed you to load an edit file which has been created by the main QSpell program - this then shows the original Quill file, with mistakes highlighted in reverse capitals. You can then use the Find function to move to the next mistake.
It had a useful crossword search, which allows you to match words using wildcards, such as "m?ga??ne" or "maga*", plus an anagram and puzzle search. The puzzle search lists all words which can be made from the letters of another word.
Advertised features included:
Title: QSPELL
Language: 68000 Machine Code
Author: David T Jones
Publisher: Eidersoft
Year of Publication: 1985
Platforms Suitable for: All Sinclair QLs and emulators
Commercial Status: Commercial
Price in July 1985: £19.95
Reviews: QL User (October 1985), QL World (November 1985)
Sources Available from: n/a
Latest Version available from: Unknown
No details of this are known - other that a reference to a spell-checker for Quill in the QL User September 1985 Summer Software Survey, and in an undated letter from Sinclair Research which lists Qspell as a program from Quantum Mechanics.
Title: QSPELL
Language: Unknown
Author: Unknown
Publisher: Quantum Mechanics
Year of Publication: 1985
Platforms Suitable for: Unknown
Commercial Status: Unknown
Price in July 1985: Unknown
Reviews: Unknown
Sources Available from: n/a
Latest Version available from: Unknown