signal strength meter

What's FM signal strength? Do you mean signal strength in the regular FM broadcast band (e.g. 87 - 108 MHz)?

eg: i would select 101 mhz frequency, then i want to measure the that 101mhz signal strength when i move from one place to another, same as that of moile phone signal strength indication

So you need either a receiver for the specific frequency with signal strength indicator (RSSI) or a spectrum monitor respectively scanning receiver.

yes, is any simple circuit available

AD8309 | 5 - 500 MHz, 100 dB Demodulating Logarithmic Amplifier with Limiter Output | Detectors | RF / IF ICs | Analog Devices

AD8309 log detector on evaluation board for only S100.

Many FM receivers utilize FM demodulator integrated circuits with RSSI output. If your FM receiver has a microammeter signal-level indicator or a LED string, you can use it.
You should calibrate this meter or LED indicator with a signal generator, to know the real signal level coming to receiver input.

There are the following problems:
1. The signal-level indicators in general-purpose FM receivers only serve to indicate, not measure, the signal levels. Using them allows e.g. to point the receiver antenna (whip) or external antenna (dipole) to a distant transmitter, to optimize the reception.
2. Most FM receivers are quite sensitive and the signals enter them not only through the antenna input connector or terminals. If you need to measure the signal level from the antenna and not signals leaking directly to receiver circuits, you should get a "professional" FM receiver built in a metal case which only responds to the input signal brought to receiver input connector.
3. Many FM demodulators are integrated circuits with RSSI ( voltage proportional to input signal) output. You can connect a voltmeter to this pin and if you calibrate this RSSI voltage against FM signal input (see 2.above), you have a good signal-level meter. Using the wideband RF logarithmic detector as recommended above (AD 8913 etc.) is not too useful as such detectors are wideband and their output responds to many signals from an antenna, not to a signal of your interest.