I needed a good platform to conduct pre-employment tests on candidates for various positions, and I came across Twolink by accident. We were initially going to go with Test Gorilla, but we needed to check out the landscape to ensure we were getting a good deal. Twolink has a free tier that is quite good. Has a load of tests, and provides results per candidate directly in my email as soon as a candidate is done. It allows me to customize the questions to a role and to add some customized questions as well. Overall, I really liked the experience. The free tier would work for most people's needs.