In 1930, he took 6th place in Zoppot (Sopot), the event won by Paulin Frydman.

In 1937, he tied for 4th place with Endre Steiner and Vasja Pirc, behind Tartakower, Ståhlberg, and Najdorf in the Jurata (4th POL-ch) competition.

He played at fourth board (+7 -3 =4) at Stockholm 1937, where he won team bronze medal.

[2] Just prior to World War II, Appel lived in Lviv, where he played in some Ukrainian tournaments.

Appel disappeared and is presumed to have died during the Holocaust, but the precise date and circumstances of his death are unknown.