The late 19th century primarily used grammar books for teaching Latin.
Latin was used for all subjects (including recess time!) as late as the end of the 18th century in France. Physics was first taught in French in 1783; cf. Lucien Gagne, C.Ss.R.'s preface to Victor Coulombe's transl. of Fr. William Most's Latin by the Natural Method.
In the 13th-16th ...
Per this post by member d_e, this verb trainer they created would be a useful supplement to whichever book, course, or tool a person may be using to learn. Maybe at some point in the future they could also create a trainer for declension. One can hope! ;)