What are some alternatives?
When comparing locize and Spare5, you can also consider the following products
POEditor - The translation and localization management platform that's easy to use *and* affordable!
Amazon Mechanical Turk - The online market place for work.
Poedit - Poedit translations editor. The best way to translate apps and sites.
SerpClix - SerpClix is a click exchange network used to send more real clicks to your Google SERP. You can click to earn money or buy clicks to rank higher on Google.
Transifex - Transifex makes it easy to collect, translate and deliver digital content, web and mobile apps in multiple languages. Localization for agile teams.
CoinWorker - Complete tasks for bitcoin.