ubiquitous
adj.
The Source Sentence and (page Number): Text-Connect pg 42
The Media is also ubiquitous- present in airports, elevators, classrooms, bars and restaurants, and hospital waiting rooms.
Context Clues: Synonym because it is showing that is present everywhere
Definition: present everywhere or in several places simultaneously
Your Original Sentence: I was ubiquitous at all my little brothers activities with school.
http://www.merriam-webster.com/dictionary/ubiquitous