When Verbester is minimised it will pop up at a determined interval to test you in the next round of words to learn. Once you have answered a certain number of words (which you can change) it will go back to sleep until the next test is due. The tests only take a few minutes and you will notice your ability to conjugate verbs grows quickly.
A handy feature that Verbester provides is the ability to create learning groups for words. Say for example you have a bunch of words that you want to learn for a week, perhaps you are going to be tested on them. You can create a new word group called, for example, LearnThisWeek. You then add the words that you need to learn and select which tenses you want to test of the words. From that point you can tell Verbester to only test you on those words. By the end of the week you will have then down and you can move onto your next group. The groups are saved so you can setup revision periods that will test the old groups.
Verbester alows you to only test within certain tense conjugations which allows you to focus on an area of weakness or one you are currently studying. This allows you to build your vocab whilst learning the structure of the new tense.
Within typing three letters of your verb you have access to the full structure of the verb tenses. Compare to searching through a verb book! This makes for a great tool to have sitting on your computer to quickly consult when required. Also, the dictionary function allows looking up of English->Spanish words or vise versa.