Today smartphones are inseparable parts of modern life and are capable of performing many desktop computers' tasks such as scientific analysis with greater convenience. Here, we present OligoCOOL, which is an Android application for analyzing nucleic sequences. This application enables users to perform several common biomedical analyses for a given nucleotide sequence. OligoCOOL is a freely accessible Android app at http://bioinf.modares.ac.ir/software/OligoCOOL, which can be a suitable tool for the experimental design in the laboratories. This application also can be used to learn the basics of nucleotide sequence analysis.