According to the official site, a short anime titled "FrFr! ~Free! short movie~ ①" will be included as Tokuten animation in Volume 1 of the Free!
BD and DVD. The official site describes episodes that are not mentioned in the main series. The titles for the short anime are "Makoto no Nayami! (Makoto's Worries)" and "Buin Bosshuu! (Recruitment of the Club Members)". The contents of Volume 2 and beyond haven't announced, so how many more of these short anime will be included (since Volume 1 has "①") is not yet known.
Source: Official Site
Story by tsubasalover