The Big Bang Theory Wiki
The Bus Pants Utilization - Leonard's App idea

Leonard explains the user interface.

The Lenwoloppali Differential Equation Scanner was the name of the handwriting-recognition differential equation solving smart phone app created by Leonard, Howard, and Raj in The Bus Pants Utilization. One just uses their smartphone, takes a picture of the differential equation, such as the Schrödinger equation, and triggered by a button-press event, an algorithm drops the results from a database. The app would use handwriting recognition, and then run the equation through a symbolic evaluation engine. A button allows for scanning a new equation, while another substitutes new values for the coefficients. Not only can one store their favorite equations, but users can also forward them to their friends or post them on Facebook right from the app. Twenty people from the university signed up for a private beta.

Handwriting-Recognition Differential Equation Solving

The spherical Bessel functions satisfy the differential equation of which Howard takes a picture, thusly named the spherical Bessel differential equation. (The spherical Bessel functions are often invoked to solve the Schrödinger equation.) If the solution is regular at the origin, equals the proper spherical Bessel functions. In the case the solution is irregular at the origin, is equal to the Neumann functions or the Hankel functions of the first and second kind. Howard cites "spherical Hankel function" from the app.

The development project was codenamed "Project Lenwoloppali" (as opposed to "Koothranardowitz") and so probably led to the naming of the application itself. Howard worked on much of the programming and an install time problem, trying to have it pick up from the libraries dynamically. Sheldon was fired twice from the project for his actions and he was excluded in the secret code designation and app name. He began working, at one point, as an independent contractor on "Project NODLEHS", later asking Howard and Raj to join him in a rival company, as well as making an attempt to sabotage the guys' project by playing his theremin. He finally joined Penny in "Project Shoe".