NetWorker is a lightweight and easy to use tool that shows network information in the menu bar. it is fully customizable and supports both wireless and wired network adapters.
Fully customizable view. You can view the following properties (both download and upload is supported):
You can choose the network adapter to observe. Both wired and wireless adapters are supported!
Adjustable refresh interval.
Choose between a byte- or bit-mode.
Use either colored or black/white icons in the menu bar.
Support for auto start.
Traffic Overview: Use this feature if you are on a volume limited plan.
Fixed a bug that prevented the main window from being shown on El Capitan.