This is an irregular verb. It follows the conjugation pattern of the verb parecer.
PresentPresente
Mi gato aparece siempre a la hora de comer.
My cat always shows up at mealtime.
PreteritePretérito indefinido
Las llaves aparecieron debajo del sofá.
The keys turned up under the sofa.
FutureFuturo
El profesor aparecerá en unos minutos.
The teacher will appear in a few minutes.