Buy once instead of Tower
2 apps in the directory cover what people use Tower for. Each one is a one-time purchase.
Tower costs about $69 a year. At that rate Fork, the cheapest dollar-priced replacement at $59.99, pays for itself in 10 months.
Read the catch on each one before you switch — a one-time price is not automatically the better deal, and we say so where it is not.
The replacements
Fork
fast native git client, one key for three machines
$59.99 Perpetual
Nothing on the site promises free major upgrades, so a paid version 3 is possible
Sublime Merge
git client that shows you the command it just ran
$99 This version
Updates stop after three years; your version keeps working but newer builds need a paid upgrade