Zoho Writer does offer text spacing adjustment (unlike Google Docs) BUT it is too coarse. Increments of 1pt are too much. To avoid a turn in a line with a widow, needs a reduction of say 0.1pt or 0.2pt and this does the job and hardly shows. To reduce spacing in a text-size line by 1pt results in... a mash.

Please include 0.1pt increments in a future update (as offered by MS Word).