Electronic toolbox is an application about electronics components. it contains detail information about electronics components.
it covers common electronics circuit for a project like
Rectifier diodes, BJTs, Power BJT, MOSFETs, Signal diodes, TVS etc

Detail information about common electronic circuits

Electronics calculator

Calculations could be performed with the app like
Resistor color code calculations
Frequency and duty cycle of 555 Timer Astable multivibrator
Inverting and non inverting Op amp gain and output voltage calculations
Difference amplifier
Transformer number of turnings
common circuit calculations
common circuit details

etc